Method of treating refractory ores.



No.[727,184. Y Patented May 5, 1903.

UNITED STATES PATENT OFF CE.

ROBERT MCKNIGHT AND MOSES SATARASKY, OF PHILADELPHIA, PENNSYL- VANIA; SAID SATARASKY ASSIGNOR TO FINLEY AOKER, OF PHILADEL- PHIA, PENNSYLVANIA.

METHOD OF TREATING REFRACTORY ORES.

SPECIFICATION forming part of Letters Patent NO. 727,184, dated May 5, 1903.

" T Application filed November 21, 1901. Serial No. 83,120. (No specimens.)

To all whom it may concern: tion is freely admitted and the fumes arising Be it known that we, ROBERT MCKNIGHT from the ore are freely carried off, but carand MOSES SATARASKY, citizens of the United ried off apart from the fumes of combustion, States,residing at Philadelphia, in the county and are led into the receptacle where the secof Philadelphia and State of Pennsylvania, ond part of our operation is carried on. In have in vented new and useful Improvements this receptacle is placed common salt or other in the Art of Treating Refractory Ores, of chlorid of an alkaline or alkaline-earth metal. which the following is a specification. This chlorid is dissolved in the water. The Our invention relates to the extraction of former is preferable, as will appear. As the IO metals from ores containing metalloids in fumes of the metalloid enter the water an cases where a chlorination of the entire body acid of the metalloid will be formed, such as of the ore is not desirable, either on account sulfuric, sulfurons arsenic, or telluric acid. of the greater facility or less expense of pro- This will react with the chlorid of the solution ducing simply an oxidation without chlorinawith the formation of a salt of the metalloid I 5 tion of the ore or for some other reason makand the alkaline or alkaline-earth metal, the ing a chlorination less desirable. chlorin being set free in a nascent state and It consists, essentially, in chloridizing the combining with the precious metal or other escaping precious or other metal values that metal that has come over from the furnace it is desired to secure and which pass over to to form a chlorid. The separation of the dif- 20 a greater or less extent with the fumes of the erent materials in the receptacle is very readoxid of the metalloid in a receptacle in which ily accomplished, the hydrogen escapes as a is contained an aqueous solution of a chlorid gas, the oxysalt of the alkaline metal is stable of an alkaline or alkaline-earth metal, such and is precipitated,thecl1lorid of the precious as will be decomposed by the acid formed by metal, if gold, remains in solution, and, if 25 the fumes of the metalloid cominginto the sosilver, precipitates as horn silver, and the lution. The alkaline or alkaline-earth metal other metals will take corresponding forms. will displace the hydrogen of the acid and set The metals in solution can simply be decantfree the chlorin in a nascent state and will ed, and those precipitated as chlorids are all then allow the latter to combine with the parvery readily volatilized and separated in that 3o ticles of the metal value carried over and remanner, as their temperature of volatiliza- I duce them to chlorids. tion is very much lower than any of the other Describing now the best method of which precipitated materials. As an example of we are at present aware, giving the details of an instance of this reaction we will takea such best method, the ore containing therecommon ore-such, for instance, as a sulfid 35 fractory metalloid is placed ina furnace and ore of an ordinary description containing '85 I is subjected to a heat sufficient with access gold and silver in a flour state. The sulfur of air to produce an oxidizing roast, no parwill come into the receptacle containing the ticular attention being paid to keeping the solution of chlorid of lime as sulfuric anhyroastatalow temperature. During this roast drid or sulfurons anhydrid, principally the 0 the refractory metalloids are oxidized and former, and there will fornr sulfuric acid, 0

pass ofi in great part, and as they pass 01f taking the reaction from this state they carry with them, Whether chem1cally or H12804 Au2 Ag2 403x312:

otherwise is not readily determinable almost all the metal that exists in the ore in afinely- 4OaSO4+2AuO1+2AbC1+2H2' 4 5 divided state, especially if the mass of the ore The hydrogen passes off, the auric chlorid reis in a finely-divided state and agitated. This mains in solution, the silver chlorid precipioperation is preferably performed in an aptates, and the calcium sulfate precipitates. paratus that will enable it to be kept com- Upon heating the dried precipitate the silver pletely away from the fumes of combustion chlorid volatilizes and passes off and is col 50 and into which the air to produce the oxidalected. As the ore will be thoroughly oxi= I00 dizedin the furnace, any metal values remaining in the furnace will be readily recovered.

Having now described our invention, What We claim, and desire to secure by Letters Pat-- cut, is

The art of treating ores containing metalloids which consists in roasting the ore with access of air and agitation but shut 06 from the products of combustion, until an oxid of the met-alloid is formed and passes off, together with the metal in the ore in a finelydivided state, collecting the fumes arising from the ore, in a receptacle containing a solution of a chlorid of an alkaline or alkalineearth metal and converting insaid receptacle, the oXid of the metalloid into an acid, and replacing the hydrogen of the acid with the altures in presence of two witnesses.

ROBERT MGKNIGHT. MOSES SATARASKY. Witnesses:

GEO. W. REED, F. E. STEBBINS. 

